Apparatus for feeding treating chemicals to boilers



Nov. 14, 1933. w BUTZLER 1,934,791

APPARATUS FOR FEEDING TREATING CHEMICALS TO BOILERS Filed Aug. 15, 1931 4 Sheets-Sheet 1 INVENTOR W a W X WZcW NOV. 14, 1933. w BUTZLER 1,934,791

APPARATUS FOR FEEDING TREATING CHEMICALS TO BOILERS Filed Aug. 15, 1931 4 Sheets-Sheet 3 I I l mvzzToR 7 W E. w. BUTZLER 1,934,791 APPARATUS FOR FEEDING TREATING CHEMICALS IO BOILERS Filed Aug. 15,1931 4 Sheets-Sheet 4 i l l Q 04 i I r' I Y I 1 1/ I 2 I I I I I 1 J J 4 9 INVENTOR W 2% Nov. .14, 1933.

Patented Nov. 14, 1933 PATENT OFFICE APPARATUS FOR FEEDING TREATING CHEMICALS TO BOILERS Edward W. Butzler, Bellevue, Pa., assignor to John M. Hopwood, Dormont, Pa.

Application August 15, 1931. Serial No. 557,303

9 Claims.

This invention relates to boiler furnaces and more particularly to a method and apparatus for feeding treating chemicals to the boiler water.

In the operation of boiler furnaces, the boiler water becomes alkaline and at times the alkalinity becomes excessive. Boiler water which is excessively alkaline is conducive to the formation of scale which is objectionable.

An object of this invention is the provision of a method and apparatus for introducing treating chemicals to boiler water in proportion to the amount of .water evaporated by a boiler during a given period of time to thereby decrease the alkalinity of the boiler water and the formation of scale.

Another object of this invention is the provision of a system whereby measured quantities of treating chemicals may be introduced, to boiler water, intermittently, and at predetermined intervals so that the total quantity of chemical introduced during a given period of time will be proportional to the amount of water evaporated by the boiler in such time period.

Other objects of the invention will, in part, be

apparent and will, in part, be obvious from the following description taken in conjunction with the accompanying drawings in which;

Figure 1 is a diagrammatic illustration of circuits and apparatus for introducing predeter- 0 mined measured quantities of treating chemicals at predetermined time intervals into the feed water delivered to the boiler of a furnace.

Fig. 2 is a view in side elevation partly in section of a measuring tank and control apparatus for governing the introduction and discharge of treating chemicals to and from the measuring tank.

Fig. 3 is a view in section of the apparatus illustrated in Fig. 2 taken on line III-III thereof.

Fig. 4 is a view in section of the apparatus illustrated in Fig. 2 taken on line IV--IV thereof.

Fig. 5 is a view partly in section of a circuit controlling device embodied in the apparatus shown in Fig. 2 taken along the line V-V of Fig. 3, and

Fig. 6 is a view partly in section of the device shown in Fig. 5 taken along the line VI-VI of Fig. 3.

Throughout the drawings and the specification, like reference characters indicate like parts.

In Figure 1 of the drawings, a feed water pump 1 driven by a motor 2 is illustrated for delivering feed water from a low pressure feed water supply line 3 to a high pressure line 4 which serves a 5 boiler or boilers (not shown). The pump illustrated is of the multiple stage rotary type although it will be understood that other types of pump may be employed without departing from the spirit or the scope of the invention.

As stated previously herein, the water in a boiler, which is operating under load, becomes alkaline and when the alkalinity becomes excessive, objectionable scale forms within the boiler. In order to reduce the alkalinity of the boiler water and thereby prevent the formation of such as objectionable scale, a supply tank 5 for storing the treating chemical in liquid form and a measuring tank 6 from which treating chemical may be delivered to the boiler water are provided. The liquid treating chemical flows from tank 5 through a pipe line 5' having a solenoid operated valve 7 therein, to tank 6 from which measured quantities of the treating liquid flow through a pipe line 8 having a solenoid operated valve 9 therein, and eductor 10 to low pressure line 3. Inductor 10 is connected across the high and low pressure lines 4 and 3, respectively.

Since the pressure in line 4 is materially higher than the pressure in line 3, feed water will flow from line 4 through a pipe 11, a velocity nozzle 30 12 of the inductor and a suction chamber 13. The feed water flowing from pipe line 4 through velocity nozzle 12 travels at a-high velocity and discharges into a pipe 14 which is connected to low pressure line 3 at the intake side of pump 1. The high velocity of the feed water passing through chamber 13 creates a region of low pressure therein, thereby inducing the flow of treating chemical from pipe 8 into chamber 13 and thence into pipe 14 from which it flows to the intake side of pump 1. The chemical treating liquid thus delivered to the intake side of the pump is forced through the pump into high pressure line 4 from which water mixed with such chemical is delivered to a boiler or boilers (not shown).

Inorder that valve 7 may be opened, when the level of the treating liquid in tank 6 reaches a predetermined low level, and closed, when the level of the liquid in tank 6 reaches a predetermined high level, a float 16 having ballast 16 therein, a switch 1'7 operated thereby and a relay 18, which is controlled by switch 17, are provided. ,Relay 18 when energized actuates an armature 19 having a contact member 20 thereon to a position in which said contact member engages a stationary contact member 21, whereby a solenoid 22, that operates valve '7, is connected across electric power-supply conductors 23 and .241.

When solenoid 22 oi. valve 7 is energized, the valve is actuated to its open position; thus liquid flows from tank 5 into measuring tank 6. When the level of the liquid in tank 6 reaches a predetermined high level, switch 17 is operated to such a position that relay 18 is de-energized, causing the contact member 20 to be disengaged from contact member 21 thereby de-energizing solenoid 22 of valve 7. When solenoid 22 is deenergized, valve 7 closes and shuts of! further flow of liquid from tank 5 to tank 6.

In order that valve 9 may be opened, to permit the flow of liquid from tank 6 into eductor 10 and thence to the low pressure side of pump 1, when the level oi the liquid in tank 6 reaches a predetermined high value, a relay 26 is provided which is jointly under the control of switch 17 and a switch 27 which is opened and closed intermittently at predetermined time intervals by means of a driving mechanism 28 that operates at a predetermined speed. Switch 27 and driving mechanism may be considered as a means whereby time control of valve 9 may be obtained.

Relay 26 comprises a solenoid 29 and an armature 30 having a contact member 31 thereon that engages a stationary contact member 32 when the solenoid is energized. Contact members 31 and 32 act as holding contact members and establish a holding circuit for the solenoid of relay 26 when the solenoid has been momentarily energized by the closure of switch 27. When the holding circuit has once been established, relay 26 will remain closed until the circuit is broken by switch 17 in response to the falling or the liquid level in tank 6 to a predetermined low value.

Relay 26 includes also a movable bar 33 having a contact member 34 thereon disposed to engage a stationary contact member 35 when relay 26 is energized. Bar 33 and armature 30 are rigidly tied together by means of strips 36 of insulating material. Thus, when switch 17 is in a predetermined position and switch 27 is closed, a circuit is completed whereby relay 26 is energized that extends from conductor 23 through switch 27, contact member 32, solenoid 29 of relay 26 and switch 17 to supply conductor 24. When relay 26 is energized and contact members 31-32 and 34-35 are closed, switch 27 is bridged by contact members 31--32 to thereby establish a holding circuit for the solenoid 29 of relay 26, and a circuit for a solenoid 37 operating valve 9. The

energizing circuit for solenoid 37 extends from supply conductor 23 through bar 33, contact 4 members 34 and 35 and solenoid 37 to supply conductor 24. Thus solenoid 37 is energized and valve 9 opened.

In case it is desirable to shut of! communication between high pressure line 4 and low pressure line 3 when valve 9 is closed, a valve 38 operated by a solenoid 38' may be provided. Solenoid 38 may be connected in parallel to solenoid 37 operating valve 9; thus valves 9 and 38 are opened and closed simultaneously.

Valve 9 will remain open, permitting treating chemical to flow into the boiler feed water as described above, until the level 0! the liquid in tank 6 reaches a predetermined low level at which time switch 17 is actuated to a position in which the holding circuit for relay 26 is interrupted and the energizing circuit for relay 18 reestablished.

When relay 26 is deenergized, solenoid 37 is deenergized thereby causing valve 9 to close. Valve 9 will remain closed until the level of the liquid in tank 6 again reaches a predetermined high level.

In response to the energization of relay l8, solenoid 22 01 valve 7 is energized thereby opening the valve. Thus, liquid flows again from tank 5 to tank 6, and continues to flow until the liquid level in tank 6 reaches a predetermined high value at which time switch 17 is operated by float 16, to a position in which relay 18 is deenergized and the circuit for relay 26 partially completed. The circuit for relay 26 will be completed when switch 27 closes. Thus when relay 26 is again energized, valve 9 will be opened to permit the flow of another predetermined quantity of treating chemical to the feed water delivered by pump 1 to the boilers.

From the above description it will be apparent that a predetermined quantity of liquid treating chemical is delivered from a source of supply to a measuring tank at which time flow of liquid from the supply tank to measuring tank is shut oil. A predetermined quantity of the treating chemical having been delivered to the measuring tank, this measured quantity is then transferred into feed water which is delivered to the boiler or boilers. When this measured quantity has been delivered to the feed water, the flow of chemical to the feed water supply line is shut oil, at which time the measuring tank is again charged with a predetermined quantity oi. treating chemical. When the measuring tank has been charged with treating chemical, this measured quantity is delivered to the feed water line at a definite predetermined time interval. Thus a system and apparatus are provided whereby treating chemical may be alternately measured and discharged or delivered to a feed water line at predetermined time intervals. The time intervals and the volume of the measured quantity being so coordinated, the total amount or treating liquid or chemical delivered to the feed water, in a given period oi time, bears a fixed proportion to the total amount of teed water evaporated by the boilers during such time period.

As illustrated schematically in Fig. 1, switch 17 comprises an hermetically sealed envelope 39 having therein a quantity of mercury as indicatedat 40. A pair of contact members 41 disposed in one end of envelope 39 controls the energization of relay 18; the relay being energized when the envelope is tilted to such a position that the mercury bridges the contact members. A pair of contact members 42 disposed at the other end of envelope 39 controls the energization oi relay 26; the relay being energized when the envelope is tilted to such a position that the mercury bridges contact members 42.

Envelope 39 is tilted from one position to the other by means of a bell crank 43 which is pivoted at 44. One arm of the bell crank is connected by a link 45 to float 16 so that as the float rises and falls, the envelope of switch 17 will be tilted alternately to the positions in which the mercury bridges contact members 42 and 41, respectively.

Switch 27, as diagrammatically illustrated,

comprises a pair of stationary contact members 46 and a bridging contact member 47 which is actuated into and out of engagement with the stationary contact members by means of a cam 48. Cam 48, as illustrated, is eccentrically mounted on a shaft 49 which is driven at a predetermined speed by driving mechanism 28.

Driving mechanism 28 comprises motor 50, preferably a constant speed motor, which is mechanically connected to cam shaft 49 by means 0! speed reduction mechanism 51. Thus, by selecting the proper gear reduction between motor 50 and cam 48, and by selecting the proper form of cam, switch 27 may be caused to engage and to be disengaged from contact members 46 at predetermined time intervals, depending upon the frequency or the number of times a measured quantity of treating liquid must be delivered from tank 6 to the feed water, in a given unit of time, to satisfy operating conditions as determined by the condition of the boiler water.

In case it is necessary to manually control the energization of relay 26, a push button switch 52 maybe utilized, As illustrated switch 52 is in parallel to switch 27 so that when closed, solenoid 29 of relay 26 is connected across supply conductors 23 and 24 provided switch 17 is in that position in which contact members 42 thereof are bridged by the mercury 40.

In Figs. 3 to 6, inclusive, the construction of tank 6, the mounting therefor and the position of solenoid operated valves 7, 9 and the mercury switch 17 is illustrated in detail.

As shown in Figs. 2, 3 and 4, tank 6 is disposed behind a panel 54 having front and side walls 55, 56 and 57, respectively. The side walls terminate in flanges 58 and 59, respectively, that extend substantially parallel to front wall 55. Tank 6 is disposed between flanges 58 and 59 and secured thereto by means of vertically extending angle members 60. One flange of each of angle members 60 is riveted to flanges 58 and 59, respectively. as illustrated more clearly in Figs. 4 and 5 and the other flanges thereof are welded to the tank at opposite sides thereof. The tank is thus rigidly held in place to prevent its toppling from one side to'another.

The tank is supported on framework comprising an angle member 62, that extends across the bottom of the tank and which is riveted to flanges 58 and 59 of panel 54. The framework also includes an upright 63 disposed under the tank as at 64 indicated in Figs. 3 and 4, and a cross piece 65 that connects angle member 62 to the upright.

The treating chemical is delivered to tank 6 through pipe 5' in which solenoid operated valve 7 is disposed. Solenoid 22 which operates valve 7 is mounted in a fluid tight housing 66 which is secured to flange 58 of panel 54 by means of clamping bands 67, the bands being riveted or otherwise suitably secured to the flange. Pipe 8 through which liquid in tank 6 flows to eductor 10 and thence to the intake side of pump 1, is attached to the bottom of tank 6. Valve 9 is disposed in pipe 8 and solenoid 37 which operates this valve is mounted in a housing 68, similar to the housing illustrated in connection with valve 7. In case it is desired to disconnect tank 6 from eductor 10 a manually operable valve 69 may be employed in pipe line 8 as shown in Fig. 2.

To prevent back-flow of feed water from high pressure line 4 through the eductor and into tank 6, a check valve 69 is provided, being located between valve 9 and the eductor.

In order that float 16 may be guided in its upward and downward movements as the level of the liquid in tank 6 rises and falls, a pair of guides 70 are provided which are disposed one near the top and one near the bottom of tank 6. The construction of guides 70 is illustrated more clearly in Fig. 4 of the drawings.

As illustrated, each guide comprises a strip 71 having flanged ends 72 which are secured to the wall of the tank, as by welding, at diametrically opposite points. The middle portion of strip 71 has a semi-circular bend 73 therein, the radius of which is slightly larger than the radius of float 16. A semi-circular band 74 disposed in complemental relation to the semi-circular bend 73, is secured to strip 71 by means of rivets, or other suitable means, as indicated at 75. Thus band 74 and the semi-circular bond 73 form a closed ring through which float 16 moves in response to changes in liquid level. Since the float is guided at its upper and lower ends in this manner, it will always remain in alinement.

Switch 17 and the operating mechanism therefor is mounted on a bracket 77 secured to front wall 55 of panel 54 at a suitable distance above the top of tank 6. Bracket 77 includes an upwardly extending plate 78, which is formed preferably as an integral part of the bracket, for supporting switch 17 and a terminal block 79 to which the contact members of switch 17 are connected and from which connections are made to relays 18, 26 and supply conductors 23 and 24, as indicated in Fig. 1.

Envelope 39 of switch 17 is carried by a clip 80 which is mounted on a stub shaft 81 journaled in plate 78. A lever 82 attached to stub shaft 81 is connected by a pin 83 to one arm of a bell crank 84 corresponding in function to hell crank 43 illustrated in Fig. 1. The knee of the bell crank is disposed between a pair of uprights 85 and turnably supported on a pin 86 that extends through uprights and the knee of the bell crank. Thus, as the bell crank turns on pivot pin 86, switch 17 is actuated from one of its circuit controlling positions to the other.

As illustrated more clearly in Fig. 6, one arm of the bell crank is materially longer than the other, and carries a weight 87 which is slidable thereon and held in place by means of a set screw 88. The short arm of the bell crank is attached to link 45 so that as float 16 either rises or falls bell crank 84 will turn either counter-clockwise or clockwise, as viewed from Figs. 2 and 6.

In order that clockwise travel of bell crank 84 may be limited, thereby to control or regulate the amount of liquid which may flow into tank 6 from tank 5 before valve 7 is closed, an adjustable stop 90 is provided in bracket 77 and disposed in line with the short arm of the bell crank.

In order to limit counter-clockwise travel of bell crank 84 thereby to regulate or control the amount of liquid which flows out of tank 6 and into the feed water, while valve 9 is open, a cam 91 is provided. Cam 91 as shown more clearly in Figs. 2, 5 and 6 comprises a cylinder which is circular in section. The end of the cylinder adjacent to the bell crank is cut on a bias or at an angle, as indicated at 92 in Fig. 6, and forms a cam surface. This cam surface is engaged by an adjustable follower 93 which is mounted on the long arm of bell crank 84. Thus as member 91 is turned in one direction or another, weight 87 on bell crank 84 may be moved towards or away from a vertical line passing through pivot pin 86, thus decreasing or increasing the force required to throw crank 84 to that position in which weight 87 comes to rest at the right of a vertical line passing through pin 86. Therefore, for any given position of cam member 91, float 16 must exert a definite force when moving in a downward direction in order to throw bell crank 84 to that position in which the short arm of the crank will come to rest on stop 90. The force exerted by float 16, in order to throw crank 84 to this position, is determined by the amount of liquid which flows from tank 6 to the feed water pump. 150

For a given position of weight 8'7 on the long arm of bell crank 84 and for a given position of cam surface 92 it will be apparent that a definite amount of liquid must flow out of tank 6 before the weight of float 16 becomes effective to turn bell crank 84 counter-clockwise to a position such that weight 87 is in line with or slightly to the right of a vertical line passing through pin 86. Thus the farther weight 87 is to the left of a vertical line passing through pin 86, the greater is the amount of liquid which must flow out of tank 6, in order that the weight of float 16 will become effective to throw the bell crank to such a position that weight 87 will be in line with or to the right of pin 86.

It will also be apparent that the farther weight 87 is to the right of pin 86, the higher must the level of the liquid in tank 6 be in order that the buoyancy of weight 16 may be suflicient to throw bell crank 84 to the position indicated either in Fig. 2 or 6. Thus by adjusting stop 90, the position of weight 8'! with respect to a vertical line passing through pin 86 may be determined and regulated to thereby regulate the amount of liquid which will flow into tank 6 before float 16 will become sufficiently buoyant to throw bell crank to the position indicated in Fig. 2 or 6.

Thus stop 90 and cam 91 act as a means for adjustably opposing the force of buoyancy exerted by float 16 on bell crank 84. Therefore, the greater the force opposing the rising movement of the float, the higher the liquid level must be in tank 6 before the bell crank can be shifted. Likewise, the greater the force opposing the lowering movement of float 16, the lower the level of the liquid in the tank must be before the bell crank will be thrown to its limiting position in a clockwise direction.

Member 91 is secured to a stub shaft 96 that extends through the front wall of panel 54 and bracket 77 and into member 91. A strut 97 secured to the inside surface of member 91 is provided as a means for attaching the irmer end of stub shaft 96 to member 91. In order that stub shaft 96 may be turned to thereby turn member 91, a hand wheel 98 is attached to the outer end of shaft 96 by means of a set screw 99. The hub of hand wheel 99 carries a pointer or indicating member 100 that cooperates with a graduated index plate 101 so that the operator may know what the exact position of bell crank 84 is. Therefore, by knowing the limit of travel of hell crank 84 in a counter-clockwise direction, the operator will know exactly how much liquid will flow out of tank 6 while valve 9 is open. Plate 101 is secured in position by means of bolts 102, these bolts also serving as a means for holding bracket 77 in position.

When beli crank 84 is thrown to a position in which weight 87 is to the right of a vertical line passing through pin 86, envelope 39 of switch 17 will occupy a position indicated by broken line 104. When in this position contact members 42 of the switch are bridged by the mercury in.

the envelope so that the circuit for'relay 26 will be partially completed and completed when time switch 2'7 is closed.

When the bell crank 84 occupies the position shown in Fig. 6, contact members 41 are bridged by the mercury in the envelope so that relay 18 is connected across power supply lines 23 and 24 thereby closing contact members 20 and 21 and energizing solenoid 22 of valve 7 whereby the valve is opened to permit liquid to flow from tank 5 to tank 6. Thus valve 7 is opened and valve 9 closed, when a predetermined amount of liquid has been transferred from tank 6 into the feed water. Valve 7 remains open until a predetermined amount of liquid has flowed from tank 5 to tank 6, as determined by the position of adjustable stop 90.

When this amount of liquid has been delivered to tank 6 float 16 becomes sufflciently buoyant to turn bell crank 84 to a position such as indicated in full lines in Figs. 2 and 6. When in this position switch 17 and switch 27 will effect the energization of relay 26 and the solenoid 3'7 of valve 9. Thus when valve 9 opens, a predetermined amount of liquid will flow from tank 6 into the feed water and the amount which flows into the feed water is determined by the position of cam 91.

It will be readily understood by those skilled in this particular art that various modifications may be made in the apparatus and the control system herein disclosed without departing from the spirit or the scope of the invention. It will also be understood that the method of introducing the treating chemical into the feed water may also be varied without departing from the spirit or the scope of the invention.

Having thus described the invention it is to be understood that only such limitations shall be placed thereon as are imposed by the prior art and the appended claims.

What I claim as new and desire to secure by Letters Patent is: I

1. In combination, a measuring tank having an inlet connected to a source of supply of liquid and an outlet connected to apparatus for utilizing said liquid, and a valve in said inlet and outlet, of a float disposed in said tank, means controlled by said float arranged to open said inlet valve and close said outlet valve, when the liquid in said measuring tank reaches a predetermined low level, and to close the inlet valve, means operating in conjunction with the float controlled means adapted to open the outlet valve when the liquid in said tank reaches a predetermined high level, and means for adiustably restraining the movement of the float, in response to changes in liquid level in said tank to thereby predetermine and regulate the quantity of liquid flowing into and out of said tank.

2. The combination with a tank having an inlet, a solenoid operated valve in said inlet, an outlet, a solenoid operated valve in said outlet, and means including a switch for alternately energizing and de-energizing the solenoids operating said valves, so that when one of said valves is open the other is closed and vice versa, of a float in said tank operatively connected to said switch for moving said switch alternately to one position and then another thereby to alternately energize and de-energize said valve solenoids, and means for adjustably opposing the force of buoyancy of said float to thereby regulate and predetermine the amount of liquid flowing into and out of said tank.

3. The combination with a container having an inlet and an outlet for liquid, and a solenoid operated valve in said inlet and outlet, of a bell crank turnably mounted on a pivot, a weight on one arm of said crank, a floatin said container connected to the other arm of said crank, a switch connected to said crank so as to be actuated from one position to another as the crank is actuated to such positions that the weight thereon is alternately on one side or the other of the pivot point, thereby to effect alternate opening and closing of said valves and means for adjustably limiting the throw of said crank whereby the amount of liquid flowing into and out of said tank may be regulated and predetermined.

4. In combination, a supply tank having therein a quantity of treating liquid, a measuring tank connected to said supply tank, a valve between said supply tank and measuring tank for controlling the flow of liquid to said measuring tank, a boiler feed water line, a valve disposed between said measuring tank and feed water line to control the flow of liquid from said measuring tank to the feed water line, a solenoid for operating each of said valves, a float in the measuring tank, means including a circuit controlling device operatively connected to said float and arranged to energize the solenoid of the valve disposed between the supply tank and the measuring tank and adapted to efiect de-energization of the valve operating solenoid disposed between said measuring tank and the feed water line when the liquid in said measuring tank reaches a predetermined low level thereby to open said first mentioned valve and to close said second mentioned valve, said float being arranged to actuate said circuit controlling device to another position when the liquid in said measuring tank reaches a predetermined high level, said circuit controlling device when in its last mentioned position eilecting de-energization of the solenoid operating the valve between the supply tank and the measuring tank thereby to close said valve, and time controlled mechanism operating conjointly with said circuit controlling device when in its last mentioned position to effect energization of the solenoid operating the valve between the measuring tank and the feed water line at time intervals.

5. In combination, a supply tank having thereinga, quantity of treating liquid, a measuring tank connected to said supply tank, a valve between said supply tank and measuring tank for controlling the flow of liquid to said measuring tank, a boiler feed water line, a valve disposed between said measuring tank and feed water line to control the flow of liquid from said measuring tank to the feed water line, a solenoid for operating each of said valves, a float in the measuring tank, means including a circuit controlling device operatively connected to said float and arranged to energize the solenoid of the valve disposed between the supply tank and the measuring tank and adapted to effect de-energization of the valve operating solenoid disposed between said measuring tank and the feed water line when the liquid in said measuring tank reaches a predetermined low level thereby to open said first mentioned valve and to close said second mentioned valve, said float being arranged to actuate said circuit controlling device to another position when the liquid in said measuring tank reaches a predetermined high level, said circuit controlling device when in its last mentioned position eflecting de-energization of the solenoid operating the valve between the supply tank and the measuring tank thereby to close said valve, and means for opposing the force of buoyancy of said float to thereby regulate and predetermine the amount of liquid that may flow into and out of said measuring tank before said float becomes efiective to actuate said controlling device to its respective circuit controlling positions.

6. The combination with a supply tank for treating liquid, a measuring tank having a connection with a feed water line, a valve between predeterminedsaid tanks, a valve between the measuring tank and the feed water line, and electro-magnets for operating said valves, of a float in said measuring tank, a switch operated by the rise and fall of said float adapted to connect the electromagnet of the valve disposed between said tanks to a source of current, when the liquid in the suppply tank falls to a predetermined level, thereby to open said valve, and to disconnect said electro-magnet from the source when the liquid in said measuring tank rises to a predetermined level, thereby to close the valve, said switch when in a position corresponding to low level position of the float causing the electro-magnet of the valve between the measuring tank and feed water line to be de-energized, and when actuated to a position corresponding to high liquid level position of the float partially completing a circuit for the electro-magnet operating the valve between the measuring tank and the feed water line, and time controlled means adapted to complete said circuit when said switch is in said high liquid level position.

7. The combination with a source of supply of treating liquid, a measuring tank having an inlet connected to the source, a valve between said inlet and source and an electro-magnet for operating said valve, and means controlled by the level of the liquid in the tank adapted to energize said electro-magnet to thereby open the valve when the level of the liquid in said tank is at a predetermined low value and to de-energize said electro-magnet when the level of the liquid rises to a predetermined high level to thereby close the valve, said tank having an outlet adapted to be connected to a feed water line, of a valve in said line, and time controlled means operating in conjunction with said liquid level controlled means for opening the valve in said outlet provided the level of the liquid in the measuring tank is at said predetermined high value, said liquid level control means operating to close the outlet valve when the inlet valve is opened as aforesaid.

8. The combination with a supply tank for treating liquid, a measuring tank having a connection with a feed water line, a valve between said tanks, a valve between the measuring tank and the feed water line, and electrical devices for operating said valves, of a float in said measuring tank, a switch operated by the rise and fall -of said float adapted to connect the electrical device of the valve disposed between said tanks to a source of current, when the liquid in the supply tank falls to a predetermined level, thereby to open said valve, and to disconnect said electrical device from the source when the liquid in said measuring tank rises to a predetermined level, thereby to close the valve, said switch when in a position corresponding to low level position of the float causing the electrical device of the valve between the measuring tank and feed Water line to be de-energized, and when actuated to a posi tion corresponding to high liquid level position of the float partially completing a circuit for the electrical device operating the valve between the measuring tank and the feed water line, and time controlled means adapted to complete said circuit when said switch is in said high liquid level position.

9. The combination with a source of supply of treating liquid, a measuring tank having an inlet connected to the source, a valve between said inlet and source and anelectrical device for operating said valve, and means controlled by the level in conjunction with said liquid level controlled means for opening the valve in said outlet provided the level 01' the liquid in the measuring tank is at said predetermined high value, said liquid level control means operating to close the outlet valve when the inlet valve is opened as aforesaid.

EDWARD W. BUTLLER. 

